This all began in October when, during regular driving, the ABS light came on, twice, then disappeared.

About a month later, I got a CEL with the engine going to half-power, and the redline restricting itself. This happened during harder acceleration (merging). The acceleration became very harsh and the entire car would rumble and vibrate during idle and standstill.

After restarting engine, light went off and engine appeared to be back to normal. Took into BMW that day, they said they couldn't find the CEL for the time I was referring to, but they did find Cylinder 2 with a misfire. Coils 1 and 2 were swapped. I was told to keep an eye out for any more CEL.

Yesterday, again during harder acceleration (low RPM, higher gear acceleration, the engine felt like it was struggling, was a bit jerky) the CEL came on again. Same thing, very harsh acceleration, rumbly/vibrations on idle and stand still.

Turned off engine, turned back on, CEL gone. Took to BMW, again they said they couldn't find anything when reading the key, and to come back with the CEL still on (so don't turn engine off when it happens).

Last night, my ABS light came on again during regular driving. Came on, then off, twice.

2008 e92 6spd with 94,000km. Original battery. I know if the battery is weak, it'll start triggering errors, but the fact that the engine physically feels affected makes me think it's not the battery. Any insight here? BMW can't seem to help me without me bringing in the car while it's displaying the CEL.

This all began in October when, during regular driving, the ABS light came on, twice, then disappeared.

About a month later, I got a CEL with the engine going to half-power, and the redline restricting itself. This happened during harder acceleration (merging). The acceleration became very harsh and the entire car would rumble and vibrate during idle and standstill.

After restarting engine, light went off and engine appeared to be back to normal. Took into BMW that day, they said they couldn't find the CEL for the time I was referring to, but they did find Cylinder 2 with a misfire. Coils 1 and 2 were swapped. I was told to keep an eye out for any more CEL.

Yesterday, again during harder acceleration (low RPM, higher gear acceleration, the engine felt like it was struggling, was a bit jerky) the CEL came on again. Same thing, very harsh acceleration, rumbly/vibrations on idle and stand still.

Turned off engine, turned back on, CEL gone. Took to BMW, again they said they couldn't find anything when reading the key, and to come back with the CEL still on (so don't turn engine off when it happens).

Last night, my ABS light came on again during regular driving. Came on, then off, twice.

2008 e92 6spd with 94,000km. Original battery. I know if the battery is weak, it'll start triggering errors, but the fact that the engine physically feels affected makes me think it's not the battery. Any insight here? BMW can't seem to help me without me bringing in the car while it's displaying the CEL.

Thanks in advance

CEL codes are stored and BMW has access to them. BS on them not being able to find them.

In response to your problem, it might be a broken valve spring causing this. I went through the same thing, where the dealer swapped coils and problem persisted during diagnosis.